If using chicken tenders, season to taste and grill or bake until cooked through, and then chop and sit aside. If using rotisserie chicken, chop and sit aside.
In a large pot, boil the pasta according to package instructions. While this is working, steam the broccoli.
While the broccoli is steaming and the pasta is boiling, make the sauce. In a skillet over medium heat, put the butter and cream. Melt the butter into the cream slowly- a low simmer is fine but don’t boil it. Season to taste with salt and pepper. Just before you drain the pasta, stir 1 ½ cups of the grated Parmesan into the butter and cream mixture and stir until melted smoothly in. Remove from heat.
Drain the pasta and return to pot. To the pot of pasta, add all of the sauce and the steamed broccoli. Stir to combine. Use the remaining grated Parmesan to top the plated alfredo. Serve with salad.